A possible fix for usb_update.img with ip900
AND
removal of "NLB BOOTING" info.

Attached you find small image for ip900 and one for ip9000.

Fastest way is to upload .img file to your /tmp folder and through webif do a firmware upgrade... file is ONLY 132KB..
It takes only 2 second..

usb_env900.zip for ip900 users
usb_env9000.zip for ip9000 users

usb_env900.zip